title: Robustness analysis of cellular memory in an autoactivating positive feedback system.
abstract: Cellular memory is a ubiquitous phenomenon in cell biology. Using numerical simulation and theoretical analysis, we explored the robustness of cellular memory to intrinsic noise in a transcriptional positive feedback system. Without noise, the system could create two stable steady states and function as a memory module. Memory robustness index and mean first-passage time were used to quantify the robustness of memory. Large cell size and strong cooperativity in binding enhanced memory storage remarkably. Adding a second positive feedback loop improved persistent memory significantly, whereas including a negative one destabilized memory storage. These are consistent with experimental observations. We interpret why positive feedback loops are actively involved in epigenetic memory from a dynamical systems perspective.
authors.affiliation: National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Cheng
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D002468:Cell Physiological Phenomena / Q000235:genetics*; D048429:Cell Size; D044127:Epigenesis, Genetic; D025461:Feedback, Physiological / Q000235:genetics*; D008957:Models, Genetic; D014158:Transcription, Genetic